1. Field of the Invention
The present invention generally relates to a pattern recognition system and more particularly to a pattern recognition system for use in defeating counterfeiting.
2. Description of the Related Art
Spatial patterns, such as logos or white-light holograms are commonly used for authentication and security. Ideally, these patterns are difficult to copy, but are easy to recognize or verify.
Alternative security devices that are conventionally used are magnetic stripes and white-light holograms. Magnetic stripes offer little security because equipment that reads, laminates, and encodes the magnetic is readily available to the public at low cost. Thus, the opportunity for counterfeiting is great. White-light holograms have decreased security because counterfeiting is becoming commonplace, and humans cannot easily detect fakes.
More specifically, spatial patterns are commonly used to show the authenticity of name-brand products, credit cards, etc. The complexity or difficulty of unauthorized reproduction of such patterns is a deterrent to counterfeiting or the like by unauthorized licensees. However, counterfeiting of difficult patterns such as white-light holograms is quickly reaching a state in which non-expert humans cannot adequately and reliably distinguish between a "fake" and the original product. This problem in human verification has created a need for machine-automated verification.
One aspect of making a pattern difficult to copy is to make the pattern difficult to discover or to obscure the pattern. For example, a laser (e.g., non white-light) hologram can be seen only under specific illumination and imaging conditions. This obscuration feature further deters or delays successful counterfeiting. Currently, there are efforts underway in the bar code industry to place hidden bar codes in holograms for this purpose. A major advantage of bar codes is the large infrastructure of the bar code industry, which may allow standard codes and readers to be used with little modification and at low cost.
However, while a hidden pattern, such as a laser hologram, makes counterfeiting difficult, the hidden pattern may make verification difficult, as mentioned above. A machine verification system that sets up the proper imaging conditions and automatically verifies the pattern is needed. Machine verification also would reduce subjectivity and increase reliability, not presently available with human verification.
However, once a counterfeiter discovers how to observe the hidden bar code by experiment or reverse engineering of an automatic verifier, the counterfeiter can easily read and reproduce the bar code. Thus, for machine verification, it also is desirable to have a simple but non-obvious algorithm so that reverse engineering the pattern and verification method is unfeasible to the unscrupulous counterfeiter.
Hitherto the invention, no such structure incorporating such an algorithm and scheme was available and there has been no exploitation of the value of using hidden patterns through the use of simple but non-obvious, non-standard patterns and verification algorithms.